Synthesis, Characterization, and Electronic Structures of Porphyrins Fused with Polycyclic Aromatic Ring Systems

Tetsuo Okujima; John Mack; Jun Nakamura; Gugu Kubheka; Tebello Nyokong; Hua Zhu; Naoki Komobuchi; Noboru Ono; Hiroko Yamada; Hidemitsu Uno; Nagao Kobayashi

doi:10.1002/chem.201602213

Synthesis, Characterization, and Electronic Structures of Porphyrins Fused with Polycyclic Aromatic Ring Systems

Chemistry. 2016 Oct 4;22(41):14730-8. doi: 10.1002/chem.201602213. Epub 2016 Aug 25.

Authors

Affiliations

¹ Graduate School of Science and Engineering, Ehime University, Matsuyama, 790-8577, Japan. okujima.tetsuo.mu@ehime-u.ac.jp.
² Department of Chemistry, Rhodes University, Grahamstown, 6410, South Africa. j.mack@ru.ac.za.
³ Graduate School of Science and Engineering, Ehime University, Matsuyama, 790-8577, Japan.
⁴ Department of Chemistry, Rhodes University, Grahamstown, 6410, South Africa.
⁵ Graduate School of Science, Tohoku University, Sendai, 980-8578, Japan.
⁶ Graduate School of Materials Science, Nara Institute of Science and Technology, Ikoma, 630-0192, Japan.
⁷ Faculty of Textile Science and Technology, Shinshu University, Ueda, 386-8567, Japan. nagaok@shinshu-u.ac.jp.

PMID: 27558988
DOI: 10.1002/chem.201602213

Abstract

A series of porphyrins fused with acenaphthylene, phenanthroline, and benzofluoranthene polycyclic aromatic rings were prepared by means of a 3+1 porphyrin synthesis approach and subsequent retro-Diels-Alder reaction of bicyclo[2.2.2]octadiene-fused precursors. Analysis of the magnetic circular dichroism spectra and the results of time-dependent DFT calculations are used to identify the reasons for the trends observed in the wavelengths and relative intensities of the Q bands of the products. Michl's perimeter model is used as a conceptual framework to explain the changes in the relative energies of the frontier π-molecular orbitals.

Keywords: cycloaddition; density functional calculations; fused-ring systems; magnetic circular dichroism; porphyrinoids.